1. Field of the Invention
The invention relates to an apparatus and a method for measuring the running gear of a motor vehicle.
2. Description of the Related Art
In known apparatuses for running gear measurement having multiple measuring units, it is necessary for their position with respect to one another to be known in the context of running gear measurement. For this, the measuring units are often mounted in a known position with respect to one another, for example on a frame. Such measurement apparatuses are relatively inflexible. In other measurement apparatuses whose measuring units can continuously determine position with respect to one another, a plurality of elements for the measuring units are necessary for the purpose, making such measurement apparatuses complex and expensive.
Published European patent application document EP 1 184 640 A2 discloses a running gear measurement device having four measurement heads for determining the wheel positions of the wheels of a motor vehicle on a measuring station. Each of the four measuring heads of published European patent application document EP 1 184 640 A2 has at least one camera, which is directed onto a measurement target disposed in the field of view of the camera, positioned in a fixed relationship with respect to the wheel of the vehicle, and aligned parallel to the wheel plane. The images of the camera are evaluated by an evaluation device in order to determine the spatial location of the measurement target, and thus of the wheel, with reference to the position of the camera or the measuring head. The running gear measurement device of published European patent application document EP 1 184 640 A2 encompasses an optical reference system for calibrating the measuring heads of the running gear measurement device with reference to the position of the measuring heads with respect to one another. A running gear measurement device of this kind is already expensive because of the obligatory presence of four measuring heads.